Saléeite mineral

Saléeite is the magnesium uranyl phosphate decahydrate mineral Mg(UO2)2(PO4)2(H2O)10 in the September 2026 IMA list, with grandfathered status G. The year 1932 denotes its original description, not a numbered IMA approval. It is distinct from lower-hydration metasaléeite, arsenate-bearing nováčekite, aluminium-bearing sabugalite, and elemental magnesium or uranium. Dal Bo and colleagues examined natural saléeite from Shinkolobwe, Democratic Republic of Congo, with associated torbernite. Single-crystal X-ray diffraction at 293(2) K supports a monoclinic P21/n structure with uranyl-phosphate sheets and hydrated interlayer magnesium. The refined saléeite cell is a = 6.9516(3), b = 19.942(1), c = 6.9667(3) angstrom and beta = 90.586(4) degrees; R1 is 0.0307 for 1990 observed reflections after the reported twin treatment. Qualitative EDS detected U, P, Mg and O but no Fe or As, whereas the crystallographic occupancy model refined 0.97(1) Mg and 0.03(1) Fe at the interlayer cation site. These are different analytical results, not proof of a chemically pure endmember. Hydrogen positions used restrained O-H distances and constrained displacement parameters. This identity and structure evidence does not establish a microbial transformation, an extraction yield, an industrial process or a universal dehydration threshold. No criticality claim is inferred from the mineral's constituents. Deposited reflection data CSD-430599 were not acquired or independently re-refined, and the separate bassetite oxidation discussion is not a saléeite experiment.

Record source: data/records/saleeite.yaml